1. Field of the Invention
The present invention relates generally to channel allocation in wideband code division multiple access (WCDMA) communication systems. More specifically, the invention relates to allocating resources in WCDMA systems and for fast channel set-up in WCDMA systems.
2. Description of Related Art
Third generation (3G) wireless communication services are rapidly being implemented on a world-wide basis, and standards for 3G systems are being developed which will implement WCDMA technology. Unlike prior narrowband code division multiple access (CDMA) systems, the 3G systems with WCDMA protocols will be versatile and specifically adapted to deliver high-speed data, high-quality sound and video services, and wideband voice services, all integrated seamlessly with Internet access. In particular, WCDMA systems have been designed for Internet-based packet-data up to 2 Mbps in stationary or office environments, and up to 384 kbps in wide area or mobile environments. Moreover, WCDMA systems are based on a completely new channel structure for all layers in the system which will greatly facilitate transport speed and greatly improve signal integrity.
The implementation of the new 3G wireless systems to integrate Internet access with high-speed data delivery will bring an ever-increasing need for fast switching and multiple channel management. From the experiences gleaned from the Global System for Mobile Communications (GSM) and other second generation (2G) systems, channel set-up and resource allocation problems inherent in such systems will be greatly multiplied in WCDMA systems, since these new systems will be heavily taxed at higher data transport rates and with denser channel requirements. Resource allocation in the transport layer of WCDMA systems and channel set-up times will be critical parameters for efficient operation of any 3G system under development. Additionally, as the international standards bodies promulgate the relevant 3G wireless communication systems standards for future implementation, transport efficiency and seamless interoperability between system vendors will require that channel set-up procedures and allocation principles be uniform and standardized. This need is particularly acute in WCDMA communication systems which will utilize a shared channel protocol.
WCDMA communication systems will have to implement fast, channel pre-reservation schemes. Such systems should maximize the use of system resources and provide for simple and efficient allocation of transport layer resources. Additionally, it would be beneficial if such WCDMA system protocols were interchangeable across all system vendors and in compliance with proposed and new 3G standards currently being promulgated.
The present invention provides for setting up channels in a WCDMA communication system through which WCDMA signals are transported in channels, and for effectively allocating WCDMA signal transport resources in the WCDMA system. A tree of channelisation codes is provided which sets out a channelisation protocol for the WCDMA communication system and which set forth channel data for formatting and transporting the WCDMA signals in particular channels. Preferably, at least one of the codes in the tree of codes is partitioned into a branch of codes which reserves transport layer resources for a channel that is assigned a code from the reserved branch. The channel is then set-up according to set-up data found in the branch of codes which relates to the channelisation protocol, thereby allocating the set of resources to the set-up channel according to the set-up data.
By pre-reserving transport layer resources in accordance with the present invention, fast channel set-up is accomplished as compared to prior channelisation techniques which have typically required a Connection Admission Control (CAC) function to verify first that there are enough transport layer resources for the new channel and that no existing connection becomes disturbed by introduction of the new channel. In 3G WCDMA systems, the invention will greatly reduce channel set-up times and will concomitantly increase data throughput in the system. This will be particularly important for high bandwidth signals that will be ubiquitous in 3G communication systems since wider data words and fast streaming data such as, for example, in video streaming will demand high performance wireless networks and Internet access. Such needs have not heretofore been fulfilled in the art.